Cubs Minor League Pitcher of Year to start vs. Mets on Thursday; Caratini Player of Year

CHICAGO -- On Wednesday, Cubs manager Joe Maddon met with Jen-Ho Tseng to talk to him about being honored as the Cubs' Minor League Pitcher of the Year. Then, Maddon surprised the right-hander with some news: Tseng will make his Major League debut on Thursday.

Tseng who was a combined 13-4 with a 2.54 ERA in 24 starts between Double-A Tennessee and Triple-A Iowa, will substitute for Mike Montgomery, who will go back to the bullpen. Montgomery was to make his 13th start of the season on Thursday in the series finale against the Mets. To make room for Tseng on the 40-man roster, right-hander Pierce Johnson was designated for assignment.

"First of all, we needed more help in the bullpen, and Monty is so versatile and was amenable," Maddon said. "He'll be availble in the 'pen tonight. Jen-Ho comes into town to accept an award. I sat down with him in my office. I said, 'I guess you're in town to accept an award.' I said, 'How about you start tomorrow night's game instead?' He didn't even blanch. His interpreter was more taken by the situation than Jen-Ho."

On Wednesday, the Cubs named Tseng and catcher Victor Caratini as the organization's Minor League Pitcher and Player of the Year, respectively. This is Tseng's second such award after also earning the honor in 2014, his first professional season.

Caratini's go-ahead home run

CHC@MIL: Caratini hits his first Major League homer

Victor Caratini crushes his first Major League home run over the center-field wall to give the Cubs a 3-2 lead in the top of the 7th

"He has four, five pitches he can throw for a strike, and he uses both sides of the plate," said catcher Taylor Davis, who caught all of Tseng's starts at Iowa. "He was really effective with all of his pitches this year, and his fastball worked well at the end of the year. It was impressive. He has a really good tempo, really good pace."

In 15 starts with Tennessee, Tseng, 22, was 7-3 with a 2.99 ERA, striking out 83 and walking 24. He was promoted to Triple-A for the first time following his first career 10-strikeout game, July 3 against Jacksonville. The right-hander excelled in Iowa, posting a 6-1 record to go along with a 1.80 ERA in nine starts.

"He got better [at Iowa]," Davis said. "I think he might have pitched with a little more confidence when he got to Triple-A. He was able to pitch really strong and didn't waste a lot of pitches. It was nice."

Maddon said the switch in starters has nothing to do with Jake Arrieta, who is still sidelined after he strained his right hamstring a week ago in Pittsburgh. Arrieta has yet to throw a bullpen session since that outing, and there is no timetable for his return.

Arrieta exits with an injury

CHC@PIT: Arrieta leaves start with strained hamstring

Jake Arrieta experiences a strained hamstring after throwing a pitch and exits his start in the 3rd inning

"We think that right now, in order to get us all set up pitching-wise, it was the right thing to do," Maddon said. "It could be one and done -- we'll see how it plays out. This guy is a really good command pitcher. He throws high 80s to low 90s [mph], with a little more velocity, kind of like [Kyle Hendricks] and has a really good changeup. He knows what he's doing out there. I spoke to him and he didn't overreact at all. I kind of liked it."

Tseng -- ranked by MLBPipeline.com as the Cubs' No. 13 prospect -- was signed as a non-drafted free agent in July 2013. He holds a career 32-20 record and a 3.17 ERA in 87 games (85 starts) across four seasons in the Cubs' system. He has been throwing at the Cubs' complex in Mesa, Ariz.

"Everybody is adamantly good with the fact that Jen-Ho will get this opportunity," Maddon said. "Lightning in a bottle happens, and you never know what happens after that. Even if it's not [another] start, maybe he'll help us in another way. David Price helped us with the Rays out of the bullpen. I'm keeping an open mind, and I'm excited about seeing it. I trust the people who are making these decisions."

Caratini, 24, batted .342 with 27 doubles, three triples, 10 homers, 61 RBIs and 50 runs scored in 83 games with Triple-A Iowa. He earned both midseason and postseason Pacific Coast League All-Star honors. His .342 average led all Cubs Minor Leaguers, and his 27 doubles were tied for the team lead.

The catcher earned his first call to the Majors on June 28. He was named to the World Team for the 2017 SiriusXM All-Star Futures Game, but did not participate due to his Major League promotion.

Carrie Muskat has covered the Cubs since 1987, and for MLB.com since 2001. She writes a blog, Muskat Ramblings, and you can follow her on Twitter @CarrieMuskat. This story was not subject to the approval of Major League Baseball or its clubs.